cesare bardeloni



C. BARDELONI.

umm; um momma RADIGTELEGRAPHIC AND RADIOTELEPHONIC SIGNALS.

AFPLICATDN ULEB APR.I2,1919.

Patented June 14, 1921.

Fly

In miur: ghiaia Per /a UNITED ASTATES PATENT OFFICE.

CESARE BARDELONI, or ROME, ITALY.

DEVICE FOB. RECEIVING RADIOTQELEGRAPHIC AND RADIOTELEPHONIC SIGN ALS.

Be it known that L-(EsARE BA" .ii/oni.' for the reception of danipcd oscillatiom` residing at Rome, in'the Kingdom d ,if have invented certain new 4andr i'isefll'l'inprovements in Devices for Receivingflac'liotelegraphic and RadiotelephonicfSignals (for which I have filed application in Italy,

' October 3, 1916); of which tliefollowing isa full, cl-ear,`and exact description, which will enable others skilled' in the art to which it appcrtains to make and use thesme.

This invention relates to devices for receiving radiotelegraphic and 'radiotelephonic signals hy means including ionized gas receivers having three electrodes andhas for its ohfiect to provide improved means for ampli ying the signal received. For said purpose an oscillating circuit u'nder the influence of the arriving waves is'connected Von one side with the incandescent `filament and on the otherside with the `grid ofthe valve, the third electrode of which is connected to the telephonie receiver, and a reetifying device is inserted across the connections of the oscillating circuit with the filament and the grid, so as t0 connect the said two elements of the valve; a potentiometer, in series with the rectifying contact being added in order' to enable the o erator to control and adjust at will the action of the device, as will he explainedihereafter.

1n theaccompanying drawings:

Figure l is' a diagram showing the usual connections of the oscillating "circuit to the ionized gas receiver. i

Fig 2 is a diagram of a receiving plant like the Valeove said comprising a rectiiying .device and .potentiometer according to the invention.

Fig. 3 is a diagram of a receiving plant` like that shown in Fig. 2. hut with the potentiometer in parallel with the rcctii'ying device and fed hy a difl'crcnt source of electrical energy from that which feeds the hot filament. i j -f Y Fig. 4 is a diagram likc that of Fig. 3, hut with the potentiometer in scricswith the rectifyingwlcvice and fcd hy the samesource of electrical cncrgy as thc filamentf"A Fig. 5 is a diagram like that 'nfl'.Fig. 4, showing an adjustahlc l. M. l". placediin the. circuit of. thc rcclitying contact.

Fig, f is a diagram of a receiving plant showing thc circuit of thc acrial directl \r connected with thc hot filament and the grid of `hc valve.

Application meap'rn 12,

Specification of Letters latent. Patient (ld Jl! Il@ i4. 19? l 1919. Serial No. 289,758.

As it is known, thc ahove named rccciwr-s.

are connected to an oscillating circuit in the manner schematically shown in Fig. l of' the drawing where 1 is the ionized gas ceivei' containing the two electrodes 2 and 3 and a wire 4 rendered iin'arulcsccnt hv this current that a suitable source (l of clcczric energy supplies to it and which is rcgulatwl by Ymeans of a rheostat To the clcctrwlrills connected a telephone apparatus 'i' which communicates with the positive pollof a suitable source of electric cncrgv. thc ucga tive pole of which is in turn connected u hh the positive pole of the incainlcsccnt ilament. The positive pole of thc filament and the electrode 2 are connected in parallel ,vifh the oscillating circuit lll and it is wcll kann u that it is advantageous to inscri a condcuscr 9 between the electrode 2 and thc a l'orcsril oscillating circuit. The tclcphonc inracafl of at 7 may he evidently placcd also :it popu 1l of the circuit. (')i course the oscilla'iug circuit 10 is suitably coupled with thc rt. ing antenna.

When a scheme of the allo'vc mentioned kind is used` a remarkable amplification wl" the signalsreccivcd is ohtaincd. and also .i high increase of scnsitivcncss of the receiver. hy' inserting a rectifier contact like. for

u:- stance. that hetwccn a stccl platc and a car liorundum"crvstal-in thc niauucr illnsfrucil in Fig. 2.

ln Fig. 2, across thc source (l of thc cur rent 'Feeding the filament is conncctcd in tlv manner shown a poicntionictcr. thc uliusf. alilc contact l2 lof. which is joined through thc rcctifying contact lil suitahl)Y iuscrlcil. to one of the onda of' thc oscillating cir! pil.. while thc-other cud ol' said circuit goce di rectly to thc clcctl'odc 2 without pas:Y ng through thc condenser l). as shown iu Fig. i. `l'n l"'ig.l thc notcntiornctcr l2 is' connected in series with thc rcctil'ving contact ll and is' provided with a cuircnt. source ll diil'cr f'viinr contact is laced ou a circuit aX-ifirur between the electrode 2 and the condenser 9 and ends at the resistance of the potentiometer 12 which is fed by the same source of electric energy which feeds the filament.

In Fig. 5, is shown the arrangement of an adjustable E. M. F. 15 placed'in the circuit of the rectifying contact 13 in series with saine and the sliding contact of the potentiometer 12 as in the foregoing case. It is obvious that such supplementary E. M. F. mayvbe equally used also in the cases shown in igs. 2, 3 and 6 or with other arrangements of circuits which, working on the principle of a rectifying device coperating with an ionized gas receiver, may receivea different form from those above mentioned. In Fig. 6 is shown the application of the invention to a form of circuitfor the recep-' tion of persistent oscillations. In said figure the electrode 2 of the ionized gasfreceiver is connected at 17, through a condenser 16 having a suitable capacity, directly to the circuit of the antenna; the electrode 3 connected with the telephone 7 is also connected to the condenser 9 which, in the schemes of Figs. 1, 3, 4 and 5, is connected in parallel at one ofthe ends of the oscillating circuit 10, the other end of said oscillating circuit being connected to that of the antenna at 18 and the two oscillating circuits, circuit 10 and that of the antenna, are connected by means of the variable coupling 19.

The action of the rectifying contact, owing to its insertion with respect to the oscillatin circuit with which/it isf'connected in aralle and with respect lto the electrode 2 o the ionized gas receiver, beassuined to be a double one:

1st-that of actiialA am lification of the si nals by the increase/o positive charges w iich flow to the electrode 2'diiifng the oscillations set up inthe oscillating circuit; 2nd-that of unificationof the ionized medium about the electrode 2, so as to `rieutralize, by means of n/egative charges'leaching to the electrode throi h the contactfthe excess of free positive c arges due to the direct influence of the electrode 2, which latter thus follows.only the charge varia tions which the aforesaid oscillating circuit im resses thereon.

aving thus described my invention what I claim is:

1. A device for detecting high frequency oscillations of the kind used for radiotelegraphic and radiotelephonic transmissions` comprising an oscillating circuit responsive to the action of the arriving waves, an ionized gas receiver with an incandescent filament. a grid and a third electrode, two

conductors which, starting from the said oscillating circuit, lead respectivel to the incandescent filament and to the grid, a rectifying device and a. potentiometer inserted in series in a conductor bridging the said two conductors which end at the filament and the grid, the potentiometer being fed b the same source of electrical energy whic feeds the incandescent filament, and a circuit comprising a tele honic or the like receiver connected to the t ird electrode. 'SZ/A device for detecting high frequency oscillations of the kind used for radiotelegraphic and radiotelephonic transmissions comprising an oscillating circuit responsive to the action'of the arriving waves,

lan ionized gas receiver with an incandescent filament, a grid and a third electrode, two

conductors which starting from the said doscillating circuit lead respectively to the in candescent filament and to the grid, a rectifying device comprising a steel plate and a carborundum crystal, a potentiometer inserted in series with the rectifying device and a conductor bridging the said two conductors which end at the filament and at the grid, and a circuit comprising a telephonie or the like receiver-,connected to the third y electrode.

3. A device ion djbecting high frequency oscillations of ye iiid used for radiotelephonic and radiotelegraphic transmis-A sions comprising an oscillating circuit on the aerial, responsive to the action of the arriving waves, an ionized gas receiver with an incandescent filament, a grid and a third electrode, two conductors which, starting from the said oscillating circuit, end res ectively at the incandescent filament an at the grid, a source of electrical energy. a rectifying device and a potentiometer inserted in series in a conductor bridging the two said conductors which end atY the filament and at the grid, a circuit comprising a telephone or like 1 receiver and a source of E. M. F., said circuit being connected to the third electrode, and a closed oscillating circuit ooupled with the oscillating circuit of the aerial and connected to the receiver on one side between the telephone and the third electrode, and on the other side between the source of electrical energy and the source of E. M. F. in the telephone receiver circuit.

In testimony whereof I afiix my signature in the presence of two witnesses.

Signed at Rome, Italy, this 8th day f!- February, 1919.

CESARE BARDELQNI Titnesses Ln'r'rnmo LAnnncmLnA, RENATO ScEvoLA. 

